Infrared reflecting device

Abstract

An infrared reflecting device includes a multi-layer infrared reflecting body composed of a plurality of superimposed infrared reflecting members, and temperature-sensitive members positioned surrounding the side faces of the multi-layer infrared reflecting body. The infrared reflecting member includes colloidal crystal particles arrayed at regular lattice spacing, and a filler interposed between the colloidal crystal particles. Depending on temperature, the temperature-sensitive members supply the filler with moisture, and the lattice spacing of the colloidal crystal particles changes due to swelling of the filler. Since lattice spacing changes the reflected wavelength from the ultraviolet region to the infrared region on the basis of Bragg's law and Snell's law, the amount of transmitted infrared radiation can be adjusted efficiently.

1. An infrared reflecting device including an infrared reflecting member for reflecting infrared radiation, the infrared reflecting member comprising:
 colloidal crystal particles arrayed at regular lattice spacing; and 
 a filler interposed between the colloidal crystal particles, the filler changing the lattice spacing of the colloidal crystal particles by expanding and contracting in response to an external stimulus and, thereby shifting reflected wavelength of the infrared reflecting member to the infrared region from a region of lower wavelength than infrared, and wherein 
 the device includes multiple layers of the infrared reflecting member, each of the multiple layers of the infrared reflecting member including colloidal crystal particles having a particle diameter differing from a particle diameter of colloidal crystal particles of at least one other of the multiple layers of the infrared reflecting member. 
 
     
     
       2. The infrared reflecting device in accordance with  claim 1 , wherein the region of lower wavelength than infrared is ultraviolet region. 
     
     
       3. The infrared reflecting device in accordance with  claim 1 , wherein
 the infrared reflecting member is configured such that a first refractive index of the colloidal crystal particles and a second refractive index of the expanding/contracting filler prior to expansion are virtually identical, and the reflected wavelength of the infrared reflecting member is shifted to the infrared region by changing the second refractive index when the filler expands. 
 
     
     
       4. The infrared reflecting device in accordance with  claim 1 , wherein
 the filler is a polymer that changes the lattice spacing of the colloidal crystal particles by absorbing/discharging a reversible movable material. 
 
     
     
       5. The infrared reflecting device in accordance with  claim 4 , further comprising a temperature-sensitive member that is placed adjacent to the infrared reflecting member and composed of a temperature-sensitive polymer, the temperature-sensitive member being configured to discharge and absorb the reversible movable material from and into the polymer of the filler depending on temperature. 
     
     
       6. The infrared reflecting device in accordance with  claim 1 , wherein the external stimulus includes electricity or light. 
     
     
       7. The infrared reflecting device in accordance with  claim 1 , further comprising a support that transmits visible light and infrared radiation, and holds the infrared reflecting member. 
     
     
       8. The infrared reflecting device in accordance with  claim 7 , wherein
 the support is a plurality of substrates that transmit visible light and infrared radiation, and 
 the infrared reflecting member is interposed between the substrates. 
 
     
     
       9. The infrared reflecting device in accordance with  claim 7 , wherein at least one of the substrates is a transparent material that transmits visible light. 
     
     
       10. An infrared reflecting device including an infrared reflecting member for reflecting infrared radiation, the infrared reflecting member comprising:
 colloidal crystal particles arrayed at regular lattice spacing; and 
 a filler interposed between the colloidal crystal particles, the filler changing the lattice spacing of the colloidal crystal particles by expanding and contracting in response to an external stimulus and, thereby shifting reflected wavelength of the infrared reflecting member to the infrared region from a region of lower wavelength than infrared, and wherein 
 the device includes multiple layers of the infrared reflecting member, each of the multiple layers of the infrared reflecting member including a filler having an expansion rate differing from an expansion rate of a filler of at least one other of the multiple layers of the infrared reflecting member. 
 
     
     
       11. The infrared reflecting device in accordance with  claim 10 , wherein the
 region of lower wavelength than infrared is ultraviolet region. 
 
     
     
       12. The infrared reflecting device in accordance with  claim 10 , wherein
 the infrared reflecting member is configured such that a first refractive index of the colloidal crystal particles and a second refractive index of the expanding/contracting filler prior to expansion are virtually identical, and the reflected wavelength of the infrared reflecting member is shifted to the infrared region by changing the second refractive index when the filler expands. 
 
     
     
       13. The infrared reflecting device in accordance with  claim 10 , wherein
 the filler is a polymer that changes the lattice spacing of the colloidal crystal particles by absorbing/discharging a reversible movable material. 
 
     
     
       14. The infrared reflecting device in accordance with  claim 13 , further comprising a temperature-sensitive member that is placed adjacent to the infrared reflecting member and composed of a temperature-sensitive polymer, the temperature-sensitive member being configured to discharge and absorb the reversible movable material from and into the polymer of the filler depending on temperature. 
     
     
       15. The infrared reflecting device in accordance with  claim 10 , wherein the
 external stimulus includes electricity or light. 
 
     
     
       16. The infrared reflecting device in accordance with  claim 10 , further comprising a support that transmits visible light and infrared radiation, and holds the infrared reflecting member. 
     
     
       17. The infrared reflecting device in accordance with  claim 16 , wherein
 the support is a plurality of substrates that transmit visible light and infrared radiation, and 
 the infrared reflecting member is interposed between the substrates. 
 
     
     
       18. The infrared reflecting device in accordance with  claim 16 , wherein at least one of the substrates is a transparent material that transmits visible light.